<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>worker performance optimization</title>
</head>
<body>
    <script>
        function calc() {
            let total = 0;
            for(let i = 0; i< 10*10000*10000; i++) {
                total += i;
            }
            return total
        }

        document.write(calc());
    </script>
</body>
</html>
